1. Field of the Invention
The present invention relates to a resist composition suitable for use in the ultramicrolithography process such as production of VLSI or a high-capacity microchip or in other photofabrication processes, and a pattern forming method using the composition. More specifically, the present invention relates to a resist composition capable of forming a high-resolution pattern by using an electron beam, an X-ray, an excimer laser or the like, and a pattern forming method using the composition.
2. Description of the Related Art
In a positive resist, the protective group in a polymer binder is deprotected by an acid generated in the exposed area to produce an alkali-soluble group and the exposed area is thereby dissolved in an alkali developer and removed, as a result, an image is formed.
As for the substrate on which the resist is coated, various substrates such as SiO2, SiON, SiN and organic BARC (bottom anti-reflective coating) are used, but these have a problem in terms of substrate surface characteristics, for example, the pattern profile deteriorates due to acidity or basicity of the substrate surface. Also, micropatterning of a resist makes it highly important to reduce the line width roughness (LWR).
To solve these problems, as described, for example, in JP-A-11-44950 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”), JP-A-2001-174982, JP-A-2000-66382 and JP-A-2002-296784 studies are being made on introduction of a sulfonamide compound, a carboxylic acid compound, a hydroxyl group-containing basic compound, a diazomethane compound or the like, but with recent progress in the micropatterning of a resist, the performance level is not satisfied any more.